1. Field of the Invention
The present invention relates generally to a portable terminal. More particularly, the present invention relates to a method and an apparatus for supporting a data service for quality of service in a portable terminal using two different operating systems.
2. Description of the Related Art
In recent 3rd Generation (3G) mobile communication, data communication is increasing at a faster rate than voice communication. In this regard, 3G Partnership Project (3GPP) and 3GPP2 are developing 3G technology of improved versions to increase data capacity. The 3GPP has developed a High Speed Downlink Packet Access (HSDPA) technique for increasing downlink capacity by improving Wideband Code Division Multiple Access (WCDMA). To increase uplink capacity, the 3GPP suggests a High Speed Uplink Packet Access (HSUPA) technique. Meanwhile, to raise data throughput, the 3GPP2 standardizes 1xEVolution Data Only (EVDO) 2-Rev 0, 1xEVDO-Rev A, and 1xEVDO-Rev B by improving the existing Code Division Multiple Access (CDMA) 2000 technology. The 1xEVDO Rev. A standard can support Quality of Service (QoS) differentiated based on a media flow among packet data services. Data services requiring the QoS include video telephony, VoIP service, and the like.
While the 1xEVDO Rev. A standard defines a common Central Processing Unit (CPU) for supporting the QoS function in the video telephony or the Voice over Internet Protocol (VoIP) service, there is no precedent where the two CPUs are implemented in a platform. That is, the common CPU supporting the QoS for the data service executes application, Session Initiation Protocol (SIP) stack, and media codec based on the single Real Time Operating System (RTOS). By contrast, two-CPU environment independently running different Operating Systems (OSs) (e.g., Mobile Windows, Linux, and etc.) does not support software architecture for the QoS support.
In a software architecture supporting the EVDO QoS with a single CPU, the EVDO Rev. A stack supporting a packet QoS resides in the bottom of a protocol stack, a Point-to-Point Protocol (PPP) module resides above the EVDO Rev. A stack, a socket resides above the PPP module, and a media codec and a SIP stack reside on the socket. An application user interface resides on the media codec and the SIP stack. The PPP module connects the socket and the EVDO Rev. A stack. That is, with the single CPU, the QoS of the EVDO Rev. A stack can be provided only through the socket and is isolated from the external CPU.
A Windows Mobile device mostly includes a modem chip and an application chip. The modem chip provides only a wireless network access function, and the application chip processes the SIP stack, the media codec, the application, and the like. Hence, there is no means for using the QoS of the EVDO in the external chip under the single CPU structure, and novel software architecture is required to support the QoS with two CPUs.
Therefore, a need exists for a method and an apparatus for supporting Quality of Service (QoS) for a data service in a portable terminal using two different Operating Systems (OSs).